Try a free chapter on Getting Started with SQL Developer
If youve ever wanted to get started with SQL Developer but didnt quite know where to start, a free chapter is being offered at http://www.oracle.com/technology/products/database/sql_developer/pdf/oraclesqldev21.pdf
for you to follow examples and learn by practice. The chapter does expect you have a computer with Microsoft Windows, Linux, or Mac OS X installed, and that you have access to an Oracle database. After initial setup just follow a quick walk-through to create connections, look at the SQL Developer landscape, and lean the general product purpose.